Adaptive Output Tracking for 1-D Unstable Heat Equations with Unknown Multi-Frequency Exosystem

Abstract

In this paper, we address the adaptive output tracking problem for a 1-D unstable heat equation with noncollocated configurations. The system is subject to disturbances and reference signals generated by a finite-dimensional exosystem, which possess multiple unknown frequencies and amplitudes. By constructing an auxiliary system and internal model dynamics, we restructure the measurable tracking error composed of available states. An adaptive method is proposed to estimate the uncertain parameters. We design an error-based adaptive dynamic compensator to achieve exponential output tracking using the backstepping method. A numerical example is provided to illustrate the effectiveness of the proposed strategy.

Keywords: Output tracking, Adaptive control, Heat equation, Unknown harmonic signals